<html>
<head>
    <link rel="icon" href="image.png"></link>
    <title>JS Prompt</title>
    <script>
    function foo() {
     alert('Test Alert');
    }
    </script>
</head>

<body onload="setTimeout(foo, 3000)">
    <div>JS Prompt</div>

    <div>
    Click the 'Mana' button, sit idle on the auth prompt

    This page will popup alert after 6 seconds

    Click cancel on the auth prompt when focus returns to this page
    </div>

    <button target="_blank", onclick="window.open('https://mana.mozilla.org')">Open Mana</button>
</body>
</html>